摘要:
A bolt has a male screw with a surface hardening portion that has an increased surface hardness and that is applied with a compressive residual stress. The male screw is formed by cutting the bolt, and performing a process to provide at least on the surface of the male screw of the bolt the surface hardening portion that has increased hardness and that is applied with a compressive residual stress. As a result, the fatigue resistance of the male screw is improved and the bolt is effective for use in a portion where the male screw is subject to a repetitive stress.
摘要:
A system calculates axial deformation of a turbine rotor. The system includes: an input part that sets measurement points of a rotor disk that constitutes the turbine rotor; a deflection amount detection part that derives radial displacement amounts of the turbine rotor for at least four or more measurement points along an outer surface in a circumferential direction of the turbine rotor based on measured values measured by a displacement gage; a storage part that stores the radial displacement amounts derived by the deflection amount detection part and measured angles at the measurement points; and a calculation part that calculates misalignment data of a most probable circle of the turbine rotor based on data stored in the storage part. At least four or more measurement points are set in the circumferential direction of the turbine rotor. The calculated circle is calculated from the displacement amount and the measured angle measured at each measurement point. The most probable circle is determined from the calculated circle, and the misalignment data of the most probable circle is calculated from the most probable circle, thereby allowing axial deformation to be calculated by a simpler method than conventional methods.
摘要:
A spherical body having a core and a surface layer is manufactured by a method comprising a preforming step in which a pair of sheet blanks (1) are formed into half-shells (11) in a two-part mold (2) having hemispherical concave mold halves by pressing each blank from one side while applying vacuum suction to the other side; a surface layer forming step in which the half-shells are loaded into another two-part mold (12) having pattern-forming projections, the core (19) is placed on one mold half, and the other mold half is joined thereto to close the mold, thereby pressing the core against the inner side of each half-shell, concurrent with which vacuum suction is applied to the outer side; and a molding step in which the surface layer is fused and solidified onto the core within the closed mold.
摘要:
A golf ball mold is prepared by inserting a dimpled hemispherical male die into a chamber in a frame, admitting hot liquid wax into the chamber, cooling and curing the wax to form a wax shape, covering the wax shape with a mix slurry of ceramic particles and a binder, drying and curing the slurry to form a ceramic shell around the wax shape, removing the wax shape from the ceramic shell, casting a molten metal into the ceramic shell, cooling and solidifying the metal to form a mold half, and removing the ceramic shell from the mold half. The mold is improved in molding precision, durability and cost.
摘要:
In a golf ball having at least a set of large and small diameter dimples, the large and small diameter dimples are of the same cross-sectional shape in their lower portion. A master model is prepared by feeding a cutter into a hemispherical surface of a master block to different depths while rotating the cutter, thereby forming a set of large and small recesses, respectively, wherein the large and small recesses have the same cross-sectional shape. The master model having plural types of dimples can be briefly fabricated and has increased freedom of design. Using the master model, a golf ball featuring uniform and densely distributed dimples can be manufactured.
摘要:
A golf ball has a coating layer made of a thermoplastic resin and formed by hot-melt coating at the surface portion thereof. For example, a two-piece golf ball is produced by enclosing a solid core with a cover material; conducting mark stamping directly on the surface of the cover material; forming, by hot-melt coating, a transparent coating layer made of a thermoplastic resin as an outermost layer; and then conducting dimple processing. The coating has a thickness in the range of 15-700 .mu.m. The coating allows the dimples to be precisely shaped and sharp edged and can be given sufficient durability and functions to improve spin properties and travel properties.
摘要:
A two or three piece golf ball in which a boundary surface between concentric solid layers has a projection formed on the surface of a concentric solid layer having a high hardness such that the projection extends along an approximate normal direction, a depression corresponding to the projection is formed in the surface of a concentric solid layer having a low hardness, and the concentric solid layer having a high hardness and the concentric solid layer having a low hardness are joined together such that the projection is inserted into the depression. A golf ball comprising a two-layer solid core is composed of a low-hardness inner core and a high-hardness outer core joined around the low-hardness inner core. A projection is formed on the inner surface of the high-hardness outer core such that the projection extends along an approximate normal direction, while a depression corresponding to the projection is formed in the outer surface of the low-hardness inner core, and the low-hardness inner core and the high-hardness outer core are joined together such that the projection is inserted into the depression.
摘要:
A golf ball having a plurality of dimples formed in its surface and a diameter of 43 to 45 mm, wherein when a phantom great circle is depicted on the ball surface to divide the ball into two hemispheres and one hemisphere is developed by Lambert conformal projection to depict a planar expansion chart, the dimples are arranged to with respect to the planar expansion chart so as to meet the requirement (I) that when the planar expansion chart has a center 0, two large and small regular triangles AABC and Aabc centered at 0 are depicted on the chart with corresponding two apexes aligned with an identical radial line from center 0, and the respective sides of the small regular triangle Aabc are extended to intersect with the sides of the large regular triangle AABC to define one regular triangle coincident with the small regular triangle Aabc, three trapezoids, and three parallelograms, six dimples are contained in the one small regular triangle, nine dimples are contained in each of the trapezoids, and four dimples are contained in each of the parallelograms, with the proviso that where a dimple extends over any two or more of the small regular triangle, trapezoids and parallelograms, the dimple is regarded to belong to the region where at least 80% of the dimple area lies.
摘要:
A method for forming a fluororesin film on a metallic substrate is described, which method comprising forming a chromium oxide film on at least one side of a metallic substrate and then forming a fluororesin film on the chromium oxide film. By this, good adhesion of the fluororesin film to the substrate is ensured. Further, when the fluororesin film is degraded, the film is readily removed without damaging the substrate and a fresh fluororesin film can be again formed on the substrate through a fresh chromium oxide film so that the substrate keeps it original dimensional precision and may be used semi-permanently.
摘要:
A golf ball is marked by directing laser light to a selected surface portion of the ball, thereby causing the exposed surface layer portion to change its color. The discolored portion forms an identification mark on the ball surface. The mark is durable and aesthetically attractive while the ball maintains dimensional precision.